BINGHAMTON, New York (CNN) -- People who knew the suspected gunman in Friday's shooting at an immigration services center were not surprised by his actions, the police chief in Binghamton, New York, said Saturday.

Police tape cordons off the crime scene in Binghamton, New York, on Saturday.

"Whatever drove this individual to do what he did I cannot possibly fathom," she said. "But we will come out of our grief and sadness more resolute in our mission and more dedicated than ever to help people realize the dream of American citizenship."

"He must have been a coward, he decided to end his own life," when he heard police sirens, Zikuski said.

By late Saturday, police had begun the grim work of notifying the family members of the victims.

Omri Yigal said one of Voong's victims was his wife, Dolores, who was taking English classes at the center to better herself. Yigal said he had no anger for the shooter.

"My thoughts are on my wife. I don't have time for that now," he said.

Yigal said he felt "grief for my wife and that's it."

"She's come so far," he said haltingly, his arms crossed and his eyes to the ground. "So much."

President Obama, speaking in Strasbourg, France, after a NATO summit, said his administration is in communication with law enforcement officials in Binghamton.

"I am heartbroken for the families who survived this tragedy and it just underscores the degree to which in each of our countries we have to guard against the kind of senseless violence that the tragedy represents," Obama said.

Authorities received a 911 phone call at 10:31 a.m. Friday from a receptionist hiding under a desk alerting them to the shooting. The receptionist, who had pretended to be dead before crawling under a desk, said she was shot in the stomach, Zikuski said. Watch Zikuski give a timeline of the shooting »

"[She's a] very brave lady," the police chief said. Police arrived on the scene minutes after the phone call; by that time, the shooting had stopped.

The woman is among the four wounded, he said; she is in serious condition.

Before entering the building's front door, Wong had apparently used his father's car to barricade the building's door, Binghamton Mayor Matthew Ryan said.

Wong then entered the building front door armed with two handguns, and without saying a word, began shooting, police said.

Ryan said two semi-automatic handguns -- a .45-caliber and a 9-millimeter -- found at the center were licensed to Wong.

Authorities executed a search warrant at Wong's home in Johnson City, just outside Binghamton, where he lived with his family, Ryan said.

"They took a computer hard drive -- they took an empty long gun case, and some other bags," he said.

State police received a tip in 1999 from a confidential informant who told them Wong was planning a bank robbery, Zikuski said. The information indicated Wong had a crack or cocaine habit and owned handguns, Zikuski said, and he did not provide additional information.

Binghamton, a city of about 50,000 people, is close to the Pennsylvania state line and about 140 miles northwest of New York City.